5 Feb 2025
Mike Davies
Job Title
Image: © Tatyana Gladskih / Adobe Stock
As a new year starts, it is worthwhile reflecting on recent developments in the pet food industry and the impact these may have on the veterinary profession.
Many factors determine the buying habits of pet owners, but three crucial factors have been identified (Phillips-Donaldson, 2023):
Common themes used by marketers on pet food labels to attract consumer interest include:
Consumer interest in the nutritional impact of specific ingredients is reported to be Innova Market Insights’ top trend for 2024 in human food, and the same pattern is occurring in pet food.
Increasing numbers of pet owners are looking to switch from traditional pet food brands with canned or pouches of wet food or dry kibble-based foods to niche foods, such as so-called “fresh”, “home-cooked” human foods, and vegetarian, vegan and raw meat based diets.
Interestingly, some of these trends are in direct conflict with recommendations by organisations such as the UN (2014) to reduce animal protein consumption to minimise environmental damage, and they also directly compete with human food producers for available food resources.
Proponents of niche foods often make derogatory claims about the health risks of feeding kibble or grain-containing foods, even though no credible scientific evidence exists to support those claims. In addition, no credible scientific evidence exists to support (often over-exaggerated) claims for the health benefits of niche foods other than poor quality publications, usually involving anecdotal reports made in online questionnaires. More well-constructed studies are needed.
Whatever trends consumers want to follow, as a profession our role is to advise our clients to feed a daily ration that is safe and meets all nutritional requirements as recommended by the FEDIAF Nutritional Guidelines 2024 (no significant changes have been made from the 2021 edition).
In theory, we should be able to recommend any food being sold with the label statement it is “complete”, but sadly in the UK, most pet foods do not comply with the guidelines (Davies et al, 2017), so further investigation is required before we can give a valid endorsement for a specific food.
Owners often take advice from friends, breeders and social media rather than the veterinary profession, and we often struggle to achieve owner compliance with feeding recommendations. Pet owners come from very different cultural, ethnic, religious, socio-economic, educational and peer-group driven backgrounds, so good, non-judgemental communication skills are really important when discussing dietary options with clients.
According to an American Animal Hospital Association report from 2009, better owner compliance can be achieved by:
Useful help on advising clients can be obtained from the Pet Nutrition Alliance at https://petnutritionalliance.org
I always try to identify which strategies are likely to work best for each client, as this can make the difference between gaining their confidence and compliance, and alienating them.
I give owners simple, clear, verbal and written instructions on how to manage their pets’ diet from day one, and give options as to how to switch foods when it is necessary.
A growing trend appears to exist in which owners give a large number of treats, snacks or supplements in addition to the main ration. This is being encouraged by companies that have introduced “toppers” to give in addition to their main meal.
When things go wrong, it can be impossible to ascertain which component of a ration may be causing a problem. I had one client who gave more than 20 different products on a random basis. It was no wonder that the dog had chronic diarrhoea, but the owner’s solution was always to add in yet another novel supplement they had read about on social media.
The sheer number of pet treats and supplements that make implied health benefit claims – such as “supports intestinal health”, “supports joint health” or “supports heart” – when no scientific evidence exists to support such statements, is astonishing and, in my opinion, requires future regulation. So, keeping abreast of scientific evidence is really important. As an example, every year millions of pounds are spent by pet owners on supplements containing glucosamine and/or chondroitin (often endorsed by veterinary practice staff), which claim to support joint health and arthritis. The scientific evidence for these claims has always been weak, non-existent or conflicting.
In a recent systematic review, (Barbeau-Grégoire et al, 2022), the authors concluded that they had found “a very marked non-effect of chondroitin-glucosamine nutraceuticals, which leads us to recommend that the latter products should no longer be recommended for pain management in canine and feline osteoarthritis”.
If true, how will the profession respond to this?
Historically, we have used novel protein foods in the management of gastrointestinal or dermatological cases involving dietary allergies or intolerances, but over the past few years, we have seen the emergence of new protein sources such as fungi, hydrolysed feather protein, cultured meat, single cell source bacteria, algae and insects (such as black soldier fly larvae, mealworms and silkworms). The main drivers for the development of these new foods have been a desire to become more sustainable, and to support pet owners wishing to reduce their family’s carbon footprint.
However, at this stage, lack of clear definitions and standardisation of measurement tools for sustainability mean we cannot be sure of just how successful these developments are, or will be. From a scientific point of view, the digestive tracts of cats or dogs do not differentiate between the origin of a protein source, and they can digest, absorb and assimilate them all.
Interestingly, and contrary to popular belief, one study (Golder et al, 2020) showed that replacing 50% of the meat in meat-based diets with plant-based proteins made no difference to overall protein digestibility in dogs or cats, and on dry diets total protein digestibility actually increased by 5% in cats.
For many years, we have noted the benefits of live bacterial cultures (probiotics) and dietary fibres that can be fermented in the colon (prebiotics) on gastrointestinal health.
Now, this has been extended to include the potential health benefits of postbiotics, which are bioactive compounds created by bacteria when they have consumed fibre or prebiotics, including lactic acid, butyrate and other short-chain fatty acids that help to maintain intestinal pH, and mucosa.
Over the past few years, associations have been found between a healthy gut microbiome and other organ system health and disease. Examples include between the gut microbiome and brain (Rhee et al, 2009), and the gut microbiome and kidney (Summers et al, 2019; Sabatino et al, 2015). This has resulted in the development and incorporation of microbiome-modifying supplements into veterinary therapeutic diets, as well as several diets used to manage gastrointestinal disease.
Many advances have been made in plant-based foods for pets, and numerous vegetarian and vegan foods are now available for dogs.
Some are also being marketed for cats, but questions still exist about whether they are complete, because not all of the essential nutrients cats require can be easily provided by non-animal sources; for example, according to the online label of one of the leading vegan cat foods (accessed 21 November 2024), it contains vitamin D2 – ergocalciferol.
Unfortunately, cats cannot use vitamin D2 and require vitamin D3 (colecalciferol). Fortunately, this is now available derived from algae, so hopefully the company will change its formula; however, it raises questions about whether cats fed its vegan food previously would be vitamin D deficient.
Similarly, synthetic taurine has been validated as safe and efficacious, and arachidonic acid has become commercially available derived from the fungus Mortierella alpina (Bajpai et al, 1991). It is only a matter of time before a complete vegetarian or vegan cat food will be produced, and subjected to feeding trials to ensure efficacy and safety.
Consumer interest and purchases of raw meat-based foods continues to grow.
The reporting of Salmonella species in dogs became a statutory requirement in England from 22 February 2021 and in Scotland and Wales from 21 April 2021; this has resulted in an increase in the number of submissions to the APHA and SRUC for Salmonella testing.
In 2023, 689 isolations from dogs were recorded. The most common serovars reported were S typhimurium (90 isolations, 13.1% of total isolations from dogs), S infantis (79 isolations, 11.5% of isolations from dogs) and monophasic S typhimurium (42 isolations, 6.1% each of total isolations from dogs). All of these serovars are of public health importance (APHA, 2024).
In total, 331 reports of Salmonella species from raw meat pet food were made, lower than during 2022 (406 reports) and higher than 2021 (295 reports). The most common serovars reported during 2023 were S Indiana (46 isolations), S Derby (31 isolations) and S infantis (29 isolations). Overall, 99 isolations of regulated serovars from raw meat pet food were reported in 2023. This is an increase of 19.5% compared with 2022 (123 isolations) and a 39.0% increase in the number of isolations in 2021 (71 isolations). The isolation rate of Salmonella species from domestic processed animal protein in 2023 was 1.2%, which is almost twice the number in 2022 (0.7%).
Globally, concerns are increasing about outbreaks of avian influenza in domestic cat populations and the associated zoonosis risk these represent. The latest case was in the US, where a cat died after the consumption of an infected turkey recipe raw pet food (Wall, 2024).
On 1 October 2024, Provet issued a press release including practical guidelines for pet owners feeding raw foods, and for raw pet food manufacturers to help reduce the zoonotic risks; this is available via tinyurl.com/n6nxwxxs
Medium-chain fatty acids have 6-12 carbon atoms in the carbon chain, mainly caprylic acid (C8) and capric acid (C10), and they are found in palm oil and coconut oil.
As medium-chain triglycerides (MCT) do not require bile salts for absorption patients with malnutrition, malabsorption or fatty-acid metabolism disorders are often treated with MCTs because MCTs do not require energy for absorption, use or storage. However, MCT oils do not contain any essential fatty acids – they are just a source of energy.
However, MCTs can have functional effects in the body and are being added to veterinary therapeutic diets because of their tendency to induce ketogenesis and metabolic acidosis. MCTs have been shown to be helpful in the management of canine epilepsy and cognitive function, either by themselves or as part of a therapeutic diet (Berk et al, 2020; Berk et al, 2021; Law et al, 2016), and they can also provide an alternate source of energy; for example, in managing cardiac disease.
The pet food market is changing dramatically; this is mainly being driven by consumer desires to feed their pets what they believe are healthier foods that will also have minimum impact on the environment.
Changes are also being driven by technical innovative developments, such as the emergence of novel protein and other ingredient sources, and recognition of health benefits from functional foods. The veterinary profession needs to be aware of these changes, keep up to date and be prepared to change practice protocols as needed.
The profession also has a key role to play in maintaining animal health by discouraging the use of products that do not work, or which may be harmful to pets or humans.
